1. Field of the Invention
This invention relates to windshield wiping systems, and more particularly, to a system and method for maintaining a windshield wash fluid in a liquid state using an internally-resistive and electrically conductive washer nozzle which is provided in a one-piece molded construction.
2. Description of Related Art
Windshield wiper systems have for many years included systems and methods for directing wiper fluid to a surface of a windshield while the wiper blades are actuated in order to wash and clean the windshield from debris, such as dirt, snow, rain and the like. In winter conditions, the washer fluid may have a tendency to freeze, particularly if an alcohol or antifreeze used in the washer fluid is evaporated sufficiently to increase the freezing temperature of the fluid above the ambient temperature in any part of the wiper system. This evaporation occurs mostly at the output or washer nozzles which directs the fluid in a spray pattern onto the surface of the windshield.
Heated nozzles have been used in the past that have a built-in heating device, such as a coil or other metallic heater, either molded into the nozzle directly or otherwise inserted into the nozzle.
In some prior applications of the heated concept, wiper blades have been provided with conduits for directing washer fluid to the windshield wherein the wiper blades comprise a heating element, such as a coil, mounted or molded directly into the wiper blade.
In U.S. Pat. No. 5,221,828 issued to Basheer et al., a thermally conductive elastomeric or rubber material is shown having a plurality of terminals which, when energized, apparently cause the wiper blade to become heated. Unfortunately, the amperage needed to heat a wiper blade of this design is estimated to be unreasonably large, such as in excess of 50 amps. This reduces or eliminates the attractiveness of the design of this approach. Also, it is believed that the engineering, tooling and surrounding apparatus, such as the wires used to couple the wiper blade to the electrical system of a vehicle makes this approach an unattractive design and relatively expensive.
What is needed, therefore, is a simple design, which is relatively easy to implement, inexpensive to manufacture and which provides a simple system and method for maintaining a washer fluid in a liquid state so the fluid may be sprayed on the windshield.